Sulfonation is an important pathway in the biotransformation of many drugs, xenobiotics, neurotransmitters, and steroid hormones. Many of the sulfonation reactions for pharmacologic agents are performed by a group of enzymes known as phenol transferases. The phenol sulfotransferase gene family consists to three members located on chromosome 16. A single gene (STM) encodes the thermolabile monoamine-metabolizing form. Two thermostable phenol-metabolizing enzymes are encoded by STP1 and STP2. Substrates for STP1 and STP2 include minoxidil, acetaminophen, and para-nitrophenol. Alterations in phenol sulfotransferase activity have been correlated with individual variation in sulfonation of acetaminophen (Reiter and Weinshilboum (1982) Clin. Pharm.) and predisposition to diet-induced migraine headaches.
The STP2 gene spans approximately 5.1 kb and contains nine exons that range in length from 74 to 347 bp. Exons IA and IB are noncoding and represent two different cDNA 5xe2x80x2-untranslated region sequences. The two apparent 5xe2x80x2-flanking regions of the STP2 gene contain no canonical TATA boxes, but do contain CCAAT elements. STP2 has been localized to human chromosome 16.
Since rates of metabolism of drugs, toxins, etc. can depend on the amounts and kinds of phenol sulfotransferase in tissues, variation in biological response may be determined by the profile of expression of phenol sulfotransferases in each person. Analysis of genetic polymorphisms that lead to altered expression and/or enzyme activity are therefore of interest.
Genetic sequence polymorphisms are identified in the STP2 gene. Nucleic acids comprising the polymorphic sequences are used in screening assays, and for genotyping individuals. The genotyping information is used to predict an individuals"" rate of metabolism for STP2 substrates, potential drug-drug interactions, and adverse/side effects. Specific polynucleotides include the polymorphic STP2 sequences set forth in SEQ ID NOs:63-100.
The nucleic acid sequences of the invention may be provided as probes for detection of STP2 locus polymorphisms, where the probe comprises a polymorphic sequence of SEQ ID NOs:63-110. The sequences may further be utilized as an array of oligonucleotides comprising two or more probes for detection of STP2 locus polymorphisms.
Another aspect of the invention provides a method for detecting in an individual a polymorphism in STP2 metabolism of a substrate, where the method comprises analyzing the genome of the individual for the presence of at least one STP2 polymorphism; wherein the presence of the predisposing polymorphism is indicative of an alteration in STP2 expression or activity. The analyzing step of the method may be accomplished by detection of specific binding between the individual""s genomic DNA with an array of oligonucleotides comprising STP2 locus polymorphic sequences. In other embodiments, the alteration in STP2 expression or activity is tissue specific, or is in response to a STP2 modifier that induces or inhibits STP2 expression.
Genbank accession no. U34804 provides the sequence of the STP2 gene.
STP2 Reference Sequences. SEQ ID NO:1 lists the sequence of the reference STP2 gene. The exons are as follows: exon 1A (nt 2591-2664); exon 1B (nt 3180-3526); exon 2 (nt 3726-3877); exon 3 (nt 3985-4110); exon 4 (nt 4196-4293); exon 5 (nt 6088-6214); exon 6 (6310-6404); exon 7 (nt 7214-7394); exon 8 (nt 7517-7712). The mRNA sequence is set forth in SEQ ID NO:2, and the encoded amino acid sequence in SEQ ID NO:3.
Primers. The PCR primers for amplification of polymorphic sequences are set forth as SEQ ID NOs:4-17. The primers used in sequencing isolated polymorphic sequences are presented as SEQ ID NOs:18-46. The primers used in Taqman assays are listed as SEQ ID NO:47-62.
Polymorphisms. Polymorphic sequences of STP2 are presented as SEQ ID NOs:63-110.